To employ stabilizers for the prevention of oil and solids separation in a peanut butter product is well known in the prior art. In general, the prior art teaches that the stabilizers can be partially or completely hydrogenated natural fats such as peanut oil, corn oil, cottonseed oil, linseed oil, palm oil, whale oil and other marine oils, alone or in combination. See U.S. Pat. No. 3,619,207, Nov. 9, 1971 to Dzurik, Hair, Hardy and Purves, (Procter & Gamble). While stabilizers form a spongy matrix of fat crystals which holds the peanut solids in suspension and the crystal structure of the stabilizer is important (Weiss, "Food Oils and Their Uses" [Avi Publishing Co., 1970] at 179), the prior art teaches the use of beta-prime tending hard fats such as hydrogenated peanut oil (U.S. Pat. No. 3,129,102, Apr. 14, 1964 to Sanders, Procter & Gamble), beta-tending hardfats such as hydrogenated peanut oil (U.S. Pat. No. 2,521,219, Sept. 5, 1950 to Holman et al., Procter & Gamble) and a combination of beta and non-beta hardfats such as hydrogenated soy bean oil and hydrogenated rapeseed oil (U.S. Pat. No. 3,265,507, Aug. 9, 1966 to Japikse, Procter & Gamble). Japikse teaches a peanut butter stabilizer which is a substantially completely hydrogenated hardstock consisting essentially of a blend of a beta-phase tending hardstock and a non-beta phase tending hardstock having a substantial proportion of fatty acid groups having from 20 to 24 carbon atoms. Suitable beta phase tending hardstocks include hard fats which have been subjected to molecular rearrangement and hydrogenation processes whereby a major amount of tristearin or tripalmitin, for example, is caused to be present in the rearranged product. Suitable non-beta phase tending hardstocks include hydrogenated rapeseed oil, mustard seed oil, and fish oils.
U.S. Pat. No. 3,671,267, June 20, 1972 to Gooding et al. (CPC International), teaches a peanut butter composition stabilized by the "stabilizing 30% of partially hydrogenated peanut oil". Gooding teaches recovering this portion by crystallization. The stabilizer which is high in symmetrical US.sub.2 G (a glyceride containing 1 unsaturated fatty acid and 2 saturated fatty acids), has a controlled amount of S.sub.3 G, and is low in U.sub.2 SG and/or unsymmetrical US.sub.2 G. Preferred ratios of these components are: 0.7 to 1.7 parts US.sub.2 G: 1 part S.sub.3 G: less than about 2 parts total U.sub.2 SG and/or unsymmetrical US.sub.2 G. Gooding et al. do not teach molecular rearrangement and produces stabilizer compositions having a much lower content of long-chain (C-20 to C-24) fatty acids as that of the present invention.
Random and directed interesterification procedures are known in the art. See, for example, Weiss (supra) pp. 60-62 and Hawley and Holman, "Directed Interesterification as a New Processing Tool for Lard" in J. Am. Oil Chemists' Soc. 33, 29-35 (1956). The purpose of the procedure is to molecularly rearrange the fatty acids of triglycerides according to the laws of chance. Then, from the randomized mixture of triglycerides, the desired triglycerides can be obtained, for example, by crystallization. In a directed interesterification, the desired triglycerides crystallize as they are formed, thus "driving" the reaction toward the desired triglycerides. In general, the temperature at which the crystallization is carried out determines which fraction of triglycerides are obtained.
While the prior art teaches the use of hydrogenated peanut oil as well as partially hydrogenated peanut oil as a stabilizer in peanut butter, no known art teaches the use of a fractionally crystallized portion of molecularly rearranged mixtures of hydrogenated and unhydrogenated peanut oils. While hydrogenation, random and directed interesterification and fractional crystallization of triglycerides are known, no one appears to have recognized these chemical process tools as means to treat peanut oil triglyceride to make an all peanut butter stabilizer as an alternative to prior art rapeseed oil-based stabilizers.